EP 826674 A1 and US 2004/92402 A1 disclose that trichloropyrimidine compounds are useful as intermediates of pharmaceuticals and agrichemicals of psychotropic drugs and herbicides.
As a process for producing the trichloropyrimidine compound, a process comprising reacting 4,6-dihydroxypyrimidine with iodine chloride to obtain 5-chloro-4,6-dihydroxypyrimidine followed by reacting obtained 5-chloro-4,6-dihydroxypyrimidine with phosphorus oxychloride is described in Journal of Chemical Society, 3478 (1955).
US 2004/9240 A1 discloses a process comprising reacting 4,6-dihydroxypyrimidine with hydrogen chloride to obtain 4-chloro-6-hydroxypyrimidine, and reacting obtained 4-chloro-6-hydroxypyrimidine with antiformin to obtain 4,5-dichloro-6-hydroxypyrimidine followed by reacting obtained 4,5-dichloro-6-dihydroxypyrimidine with thionyl chloride.